CVE-2017-6681 in Ultra Services Framework
Summary
by MITRE
A vulnerability in the AutoVNF VNFStagingView class of Cisco Ultra Services Framework could allow an unauthenticated, remote attacker to execute a relative path traversal attack, enabling an attacker to read sensitive files on the system. More Information: CSCvc76662. Known Affected Releases: 21.0.0.
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Analysis
by VulDB Data Team • 12/27/2020
The vulnerability identified as CVE-2017-6681 resides within the AutoVNF VNFStagingView class of Cisco Ultra Services Framework version 21.0.0, representing a critical security flaw that exposes the system to unauthenticated remote exploitation. This vulnerability specifically targets the framework's handling of file paths during virtual network function staging operations, creating a pathway for malicious actors to manipulate file access mechanisms. The issue stems from insufficient input validation and improper sanitization of user-supplied path parameters, allowing attackers to craft malicious requests that traverse the file system beyond intended boundaries. The vulnerability has been catalogued under CWE-22, which specifically addresses Improper Limitation of a Pathname to a Restricted Directory, commonly known as Path Traversal or Directory Traversal attacks. These attacks exploit weaknesses in input validation by manipulating file path references to access files outside of the intended directory structure, potentially leading to unauthorized data access and system compromise.
The operational impact of this vulnerability extends beyond simple information disclosure, as it enables attackers to execute arbitrary file reads on the affected system. An unauthenticated remote attacker can leverage this flaw to access sensitive system files, configuration data, and potentially confidential information stored within the application's file system. The implications are particularly severe given that the vulnerability affects the Ultra Services Framework, which typically handles critical network function operations and may contain privileged system information. Attackers could potentially extract database credentials, application configuration files, or other sensitive artifacts that could facilitate further exploitation. The attack vector requires no authentication, making it particularly dangerous as it can be exploited by anyone with network access to the affected system. This aligns with the ATT&CK framework's technique T1083, which covers File and Directory Discovery, as the vulnerability enables attackers to enumerate and access files within the system's file structure without proper authorization.
The technical exploitation of this vulnerability involves crafting malicious requests that include directory traversal sequences such as ../ or ..\ in file path parameters. When the AutoVNF VNFStagingView class processes these requests, it fails to properly validate or sanitize the input, allowing the traversal sequences to be interpreted by the underlying file system. The vulnerability's impact is amplified by the fact that it affects the staging view functionality, which is likely used during the deployment and management of virtual network functions, making it a prime target for attackers seeking to access system configuration data or sensitive deployment artifacts. The affected release version 21.0.0 of the Cisco Ultra Services Framework represents a specific software version where this flaw was present, indicating that organizations running this particular version would be exposed to the risk. Security professionals should note that such path traversal vulnerabilities often indicate broader architectural issues with input validation and access control mechanisms, suggesting that additional vulnerabilities may exist within the same codebase or similar components. Organizations should implement immediate mitigations including input validation controls, proper path normalization, and access restriction measures to prevent unauthorized file system access. The vulnerability demonstrates the critical importance of secure coding practices and proper input sanitization in preventing common attack patterns that can lead to significant security breaches.